In 1924 a curious network of catacombs was discovered in Washington D.C. They were traced to Harrison Dyar, a Smithsonian entomologist who had been industriously digging tunnels in the city for almost two decades. In this week's episode of the Futility Closet podcast we'll describe Dyar's strange hobby -- and the equally bizarre affairs in his personal life.

We'll also revisit balloons in World War II and puzzle over a thief's change of heart.

Intro:

The melody of Peter Cornelius' 1854 composition "Ein Ton" is a single repeated note.

Japanese puzzle maven Nob Yoshigahara devised this optical illusion.

Sources for our feature on Harrison Dyar:

Marc E. Epstein, Moths, Myths, and Mosquitoes, 2016.

Marc E. Epstein and Pamela M. Henson, "Digging for Dyar: The Man Behind the Myth," American Entomologist 38:3 (July 1, 1992), 148-169.

Ryan P. Smith, "The Bizarre Tale of the Tunnels, Trysts and Taxa of a Smithsonian Entomologist," Smithsonian, May 13, 2016.

John Kelly, "Who Was Harrison G. Dyar?", Washington Post, Oct. 27, 2012.

John Kelly, "Inside the Tunnels of Washington's Mole Man, Harrison G. Dyar," Washington Post, Nov. 3, 2012.

John Kelly, "A Final Look at D.C.'s Tunnel-Digging Bug Man," Washington Post, Nov. 7, 2012.

Associated Press, "Secret Tunnels Shrouded in Mystery," Oct. 21, 1992.

United Press, "Scientist Admits He Dug Tunnels That Caused Furore," Sept. 28, 1924.

Modern Mechanics published this diagram of Dyar's B Street catacomb in its August 1932 issue. The inset photo at top left corresponds to the 32-foot shaft at right, which was lined in concrete and fitted with iron pipes to serve as ladder rungs. Two more shafts (partially obscured) can be seen to the left. The inset photo at bottom shows the inscription H.G. DYAR FEB 14 1923 on an archway near the cellar entrance. That date was Dyar's 57th birthday.

Listener mail:

David Hambling, "How 100,000 Weather Balloons Became Britain's Secret Weapon," Guardian, Sept. 15, 2016.

Wikipedia, "Operation Outward" (accessed Sept. 24, 2016).

Wanderlust has a short video about the operation.

This week's lateral thinking puzzle was devised by Sharon, who offers these corroborating links (warning -- these spoil the puzzle).

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Many thanks to Doug Ross for the music in this episode.

If you have any questions or comments you can reach us at [email protected]. Thanks for listening!